President Trump declared his strong support for Saudi Arabia on Tuesday, effectively ignoring the CIA’s conclusion that Crown Prince Mohammed bin Salman ordered the brutal killing of journalist Jamal Khashoggi and asserting that relations with a critical ally should not be derailed.

In an exclamation-mark-packed statement that aides said he dictated himself, Trump said that U.S. intelligence would continue to “assess” information but that the United States “may never know all the facts surrounding the murder.”

Speaking of whether the crown prince knew about or ordered the killing by Saudi agents last month in the Saudi Consulate in Istanbul, Trump said “maybe he did or maybe he didn’t!” But the president indicated that U.S. interests in Saudi oil production, weapons purchases and support for administration policies in the Middle East were more important than holding an ally to account, and he stressed the importance of staying in the kingdom’s good graces.

“They have been a great ally,” he said of the Saudis, and “the United States intends to remain a steadfast partner.” Speaking later to reporters as he left the White House for his Florida resort, Trump said, “I’m not going to destroy our economy by being foolish with Saudi Arabia,” he said.

Trump’s defense of Saudi Arabia, whose leaders have denied knowledge of the operation while acknowledging that its agents carried it out, marks another instance when he has sided with the personal assurances of an autocrat over the analysis of his own intelligence officials.

He also took the word of Russian President Vladi­mir Putin that he didn’t interfere in the 2016 election, despite the unanimous conclusions of the U.S. intelligence community to the contrary. And Trump continues to praise North Korea’s dictator, Kim Jong Un, and declare the threat from its nuclear-weapons program neutralized, even though U.S. intelligence is still tracking the development of missiles and nuclear weapons material.

Trump and Mohammed are likely to come face to face this month at the Group of 20 meeting in Buenos Aires, which both are scheduled to attend. Turkish officials said the crown prince has requested a meeting there with Turkish President Recep Tayyip Erdogan, who has all but directly accused him of ordering the killing of Khashoggi, a contributing columnist for The Washington Post who had lived in the United States since leaving the kingdom last year out of what he said was fear for his safety.

Tuesday’s startling presidential statement was quickly condemned by lawmakers on both sides of the aisle.

“I never thought I’d see the day a White House would moonlight as a public relations firm for the Crown Prince of Saudi Arabia,” Sen. Bob Corker (R-Tenn.) wrote on Twitter.

Corker, the chairman of the Senate Foreign Relations Committee, must decide whether to use the handful of days left in the legislative term to consider a bipartisan bill, introduced last week, to stop virtually all U.S. weapons sales and military assistance to the Saudis in response to both the war in Yemen and Khashoggi’s killing. A similar measure has been introduced in the House.

Sen. Robert Menendez (N.J.), the ranking Democrat on the committee, joined Corker in sending a letter to Trump on Tuesday demanding that the administration make a determination specifically addressing whether Mohammed was responsible for the killing.

Sen. Lindsey O. Graham (R-S.C.), a Trump confidant, co-sponsored the Senate bill and said in a statement that he believed there would be “strong bipartisan support for serious sanctions against Saudi Arabia, including appropriate members of the royal family, for this barbaric act which defied all civilized norms . . . I fully realize we have to deal with bad actors and imperfect situations on the international stage. However, when we lose our moral voice, we lose our strongest asset.”

Democrats cast the president’s decision as a failure of leadership.

Sen. Mark R. Warner (Va.), the top Democrat on the Senate Intelligence Committee, said Trump’s “failure to hold Saudi Arabia responsible in any meaningful way . . . is just one more example of this White House’s retreat from American leadership on issues like human rights and protecting the free press.”

The Post’s publisher and CEO, Fred Ryan, also heavily criticized the president’s statement.

“President Trump’s response to the brutal murder of journalist Jamal Khashoggi is a betrayal of long-established American values of respect for human rights and the expectation of trust and honesty in our strategic relationships,” he said in a statement. “He is placing personal relationships and commercial interests above American interests in his desire to continue to do business as usual with the Crown Prince of Saudi Arabia.”

Trump indicated that he would fight congressional efforts to curtail the U.S-Saudi relationship. “I understand there are members of Congress who, for political or other reasons, would like to go in a different direction — and they are free to do so,” he said in his statement. “I will consider whatever ideas are presented to me, but only if they are consistent with the absolute security and safety of America.”

The Post reported last week that the CIA had determined it was effectively impossible that such an operation could have been carried out without the approval of Mohammed, the son of King Salman and the country’s de facto leader. Many of the 18 people the kingdom has said it arrested in connection with the crime were members of the royal guard, and two top aides to the crown prince were reportedly fired. On Sunday, Trump said he was awaiting a full briefing on intelligence conclusions.

The agency’s assessment relied on audio recordings provided by Turkey and intercepted phone calls, as well as other analysis work performed by Saudi experts at the CIA, according to people familiar with the agency’s work. Trump had already received intelligence briefings on the matter, and CIA Director Gina Haspel had shown the president details of the crown prince’s involvement.

It wasn’t clear that he had received any additional information before issuing Tuesday’s eight-paragraph statement. The CIA declined to comment.

The statement — titled “America First!” — began: “The world is a very dangerous place!”

Trump went on to describe the danger posed by Iran. In addition to fighting proxy wars and supporting terrorists, he said, “the Iranians have killed many Americans and other innocent people throughout the Middle East,” and Iran “states openly, and with great force, ‘Death to America!’ and ‘Death to Israel!”

“On the other hand,” he continued, Saudi Arabia has “agreed to spend billions of dollars in leading the fight against Radical Islamic Terrorism.” He lauded U.S.-Saudi economic ties and personally took credit for what he called historic Saudi investments here.

“After my heavily negotiated trip to Saudi Arabia last year, the Kingdom agreed to spend and invest $450 billion in the United States. This is a record amount of money,” Trump claimed, citing a figure that many experts have said greatly exaggerates the real value of Saudi deals.

Since Saudi Arabia first acknowledged that Khashoggi had been killed in an operation at its Istanbul consulate, Trump has repeatedly emphasized the economic aspects of the relationship, and the statement again stressed his concern that Saudi investments here could be canceled and that major defense contracts would go instead to Russia and China.

Russia has been actively courting Saudi weapons purchases, and Riyadh, despite U.S. urging, has declined to say that it will rebuff those entreaties. An internal Saudi memo obtained by The Post, confirmed as genuine by a Saudi official close to the government with knowledge about the topic, indicated that Mohammed, in the weeks before a trip he made to Moscow in June, was briefed on what the Russians could provide. The list included equipment and training for ground forces, major weapons systems such as the S-400 antimissile defense system along with reconnaissance ships, and electronic warfare and other intelligence equipment.

In the memo, dated June 15, 2018, the day after Mohammed met with Putin, he repeated those options and asked the head of Saudi defense development to “provide your vision on this matter.”

Trump also referred to Saudi Arabia as “after the United States . . . the largest oil producing nation in the world,” and said the Saudis have been “responsive to my requests to keeping oil prices at reasonable levels.” Trump indicated that in anticipation of the reimposition of U.S. sanctions on Iranian oil exports early this month, he had made a deal with Riyadh to keep its own production high to avoid a spike in oil prices.

But U.S. sanction waivers granted to most of Iran’s major customers have kept prices unusually low, and the Saudis said last week that they intended to cut production.

Trump took up a Saudi claim, fanned by some on the American political right, that Khashoggi was seen as an “enemy of the state” and a member of the Muslim Brotherhood, an Islamist group opposed by Riyadh, although he described the killing as “a horrible crime.”

But the reference amounted to an unsubstantiated slur of Khashoggi, a U.S. resident, who although he had friends within the movement had also once been a loyal supporter and close ally of the Saudi royal family.

Trump insisted that “my decision was in no way based on that,” referring to the claims that Khashoggi was a danger to Saudi Arabia. When The Post first reported on Nov. 1 that the crown prince privately described Khashoggi as a dangerous Islamist to senior administration officials, Saudi officials denied making any such claims and portrayed Khashoggi as a friend of the kingdom.

Even before the Khashoggi killing, Saudi Arabia’s conduct in the ongoing war in Yemen, which Mohammed launched in 2015 in his role as defense minister, had led to calls by lawmakers for reducing the relationship. The conflict has become a bloodbath, with thousands of casualties blamed on Saudi airstrikes and many more dead or dying from starvation.

While both Saudi Arabia and the United States have tried to refocus attention on Iranian support for Houthi militias on the other side of the fighting, the Saudis have come in for heavy global criticism. Earlier this month, the administration said it would end U.S. refueling of Saudi jets striking Yemen, although other logistical and intelligence support has continued.

It was Iran, Trump said, that was responsible for the war, and for “trying to destabilize Iraq’s fragile attempt at democracy, supporting the terror group Hezbollah in Lebanon, propping up dictator Bashar Assad in Syria (who has killed millions of his own citizens), and much more.”

“Saudi Arabia would gladly withdraw from Yemen if the Iranians would agree to leave,” Trump said in his statement. “They would immediately provide desperately needed humanitarian assistance.”

In addition to its support against Iran, Trump said, the Saudi-U.S. partnership also helps “ensure the interests of our country, Israel and all other partners in the region.” The administration has been counting on Saudi Arabia to lead the Arab world in supporting its still-unrevealed plan to forge a peace agreement between Israel and the Palestinians.

The statement, and further comments by the secretary of state, Mike Pompeo, left little doubt that, as far as the administration was concerned, relations with Saudi Arabia would continue as normal and that Trump planned to put the Khashoggi crisis behind him.

“It’s a mean, nasty world out there. The Middle East in particular,” Pompeo told reporters. “It is the president’s obligation and indeed the State Department’s duty as well to ensure that we adopt policy that furthers America’s national security. So as the president said today, the United States will continue to have a relationship with the kingdom of Saudi Arabia.”

John Hudson, Carol Morello, Tom Hamburger and Karoun Demirjian and Loveday Morris contributed to this report.